The invention relates to agents for treating keratin fibers, consisting of at least two spatially separate preparations, to the use thereof, and to a method of treating human hair.
The requirements which users of agents for treating keratin fibers, in particular hair treatment agents, place on these agents have continuously increased over time. This has led inter alia to these agents consisting in many cases of an ever greater number of components in order to achieve all of the effects desired by the user in the most optimal manner possible. However, as the complexity of these mixtures increases, so too does the number of active ingredient combinations which, despite having the desired properties in a single formulation, particularly in the case of an aqueous mixture, are no longer storage-stable.
In the field of hair treatment, a number of agents are known which are in the form of separate preparations which are either mixed directly prior to application to the hair, or are applied to the hair one after the other in separate steps; for ease of handling for the user and not least to minimize packaging expenditure, in the development of new products, wherever possible formulation in the form of one agent is desired.
Should formulation in separate preparations which have to be mixed prior to application to the hair be absolutely unavoidable, then the mixing operation should be as rapid and uncomplicated as possible, and, as already mentioned above, the additional packaging expenditure be kept as low as possible.
We have now found that these requirements are satisfied to a high degree when the component to be stored separately, or the components to be stored separately are provided with an envelope which, when the 5 preparations are combined, permits mixing of the components of the two preparations in a period of time which is tolerable for the user. The period of time accepted by the user can generally be regarded as an interval of up to 5 minutes if the mixing operation of the two preparations is not combined with any further, laborious procedures, e.g. continuous stirring, of any kind.
The invention must then firstly provide an agent for treating keratin fibers, consisting of at least one aqueous preparation A and, spatially separate therefrom, at least one preparation B, which has an envelope of preparation B made from a material which permits the components of the two preparations to mix at 38xc2x0 C. within 5 minutes when the preparation B is added to a preparation A.
A number of hair treatment agents are applied to the hair in gently warmed form. Warming is generally achieved by combining components which liberate heat on mixing. One component is often an anhydrous salt which dissolves in an aqueous phase with the liberation of heat; alternatively, it is also possible to use heats of neutralization, heats of mixing liquid components etc. The quantitative ratios of the components to be mixed are in these cases preferably adjusted such that the mixture adopts a temperature slightly above the temperature of the human body, i.e. about 38xc2x0 C., within a very short time, i.e. a few seconds. In the case of this type of agent, it is therefore sufficient for the components of the enveloped preparation B to be mixed with the components of the aqueous preparation A within 5 minutes at a temperature of 38xc2x0 C. Apart from occasional shaking of the mixture, no further activities on the part of the user should be necessary here.
The overwhelming majority of hair treatment agents are stored at room temperature and also applied to the hair at this temperature. According to a preferred embodiment of the invention, the envelope of the preparation B is thus chosen such that mixing of the components of the preparations A and B takes place within a maximum of 5 minutes even at room temperature, i.e. in particular a temperature of 20xc2x0 C.
According to a preferred embodiment of the invention, the envelope of component B is a capsule.
Corresponding envelopes in capsule form are known from the field of pharmacy. One type of these capsules are films in capsule form, in which the substances to be enveloped are completely enclosed by a layer of the enveloping material, and the enveloped substances can be released again only following destruction of the envelope. In this connection, suitable materials for the envelope are preferably certain cellulose derivatives, polyacrylates, polymethacrylates, polyvinylpyrrolidones, and, in particular, polyvinyl alcohols. In this connection, express reference is made to the monograph by K. H. Bauer, K. H. Frxc3x6mming and C. Fxc3xchrer, Pharmazeutische Technologie [Pharmaceutical Technology], Gustav Fischer Verlag, Stuttgart, Jena, Lxc3xcbeck, Ulm, 4th edition, 1997, pages 315-323.
Two-part capsules generally consist of two cylindrical halves, each sealed at one end. The internal diameter of one half, which is also referred to as the capsule cap, is slightly larger than the external diameter of the other half, referred to as the capsule base, meaning that the two halves can be inserted into one another to envelope the component to be enclosed, the capsule being xe2x80x9cboltedxe2x80x9d by special devices. This type of capsule is also referred to as hard capsules and is a preferred envelope according to the invention. Suitable capsule materials are in principle both gelatins and also synthetic or natural polymers. Polyvinyl alcohol has proven to be a particularly suitable envelope material.
In accordance with a first preferred embodiment, the entire hard capsule consists of polyvinyl alcohol.
It may, however, also be provided that only part of the hard capsule, in particular the capsule cap or parts of the capsule cap, consists of a water-soluble material in accordance with the definition according to the invention. It is then possible, for example, to prepare the capsule base from a less water-soluble material. This allows greater flexibility in setting the desired mechanical properties, e.g. the rigidity, of the capsule. With regard to this envelope form, reference is likewise made to the monograph mentioned above by K. H. Bauer, K.-H. Frxc3x6mming and C. Fxc3xchrer, pages 324-335.
The envelope can, however, also take the form of a pouch. Such pouches are produced in a known manner from polymer films, from which the individual pouches containing the ingredients are produced by sealing or gluing. Further information about such pouches is given, for example, in the article by J. Korn, Die Neue Verpackung [The New Package], 10, 1150-1155 (1962), and EP 493 392, in which pouches made of polyvinyl alcohol are disclosed for the dust-free packaging of bleaches.
Because of better handleability, particularly when the preparation B is added to a preparation A in a bottle with a relatively narrow neck, an envelope in the form of a capsule is preferred according to the invention.
It is further preferred that the envelope material consists of substances which additionally develop positive properties in hair treatment agents. In this connection as well, polyvinyl alcohol is a preferred envelope material because of its conditioning properties.
The thickness of the envelope is chosen by the person skilled in the art such that, on the one hand, a hermetic seal of the preparations to be enveloped is ensured, but, on the other hand, the mixing of the preparations A and B is not unnecessarily prolonged by too thick an envelope. Envelope thicknesses in the range from 10 to 30 micrometers have proven particularly suitable within the scope of the teaching according to the invention.
The teaching according to the invention is particularly suitable for agents which, in the preparation B, contain a constituent which is not storage-stable in the preparation A.
In accordance with a first preferred embodiment, this constituent is a perfume oil, a particular perfume component or a mixture of perfume oils.
Certain hair treatment agents comprise active ingredients which are unavoidable for achieving the desired properties or for formulating the agent, but develop such an intrinsic odor that perfume is virtually essential in order to achieve acceptance on the part of the user. Examples thereof are, in particular, permanent wave agents with a content of organosulfo compounds such as thioglycolic acid, salts and/or derivatives thereof as reducing agent, and of ammonia or lower amines for setting the pH. Both because of the reducing agents present in the agent and also because of said alkylating agents, the person skilled in the art is very limited with regard to perfume components which can be used if his task is to formulate agents which are storage-stable for months. On the other hand, most of the perfume components which are unsuitable for such storage-stable agents are sufficiently stable in the agents for a short period of time of up to an hour, i.e. for the period of time of actual use, to develop the desired scent effect.
Other agents according to this embodiment are permanent wave fixatives which are usually very acidic and contain up to 12% by weight of an oxidizing agent, in particular hydrogen peroxide. Under these conditions too, although many perfume components are stable for the period of time of application to the hair, they are not stable for months or years. Other agents in which incompatibilities arise between perfume components and further constituents are, for example, oxidation colorants and bleaching agents.
The teaching according to the invention is particularly suitable for perfume oils and perfume components which have an aldehyde function and/or a Cxe2x80x94C-double bond which optionally stands in conjugation to the aldehyde function. Other perfume components which have a primary alcohol function or an ester function are likewise preferred compounds within the scope of this embodiment of the invention.
Furthermore, perfume components of the xe2x80x9cfruityxe2x80x9d scent direction in very many cases have unsatisfactory stabilities in agents which have strong reducing or oxidizing agents. The teaching according to the invention has proven extraordinarily well suited for these perfume components as well. Finally, the same is also true for so-called sandalwood fragrances, both of natural and, in particular, of synthetic provenance.
According to a second preferred embodiment, the incompatible constituent is a substance from the group formed from vitamins, provitamins and their derivatives. This group comprises, for example, panthenol and its derivatives, such as pantothenic acid, pantothenyl esters and ethers and pantothenyl ethyl ether. Panthenol in particular is itself not sufficiently storage-stable in strongly alkaline or acidic, aqueous media, and in preparations containing oxidizing agents. Other vitamins from the B complex are the vitamins B2, B6, B12 and nicotinamide. Retinol and other substances which are referred to as vitamin A are, for example, sensitive toward oxidizing agents, and the same is true for vitamin E.
The nature of the hair treatment agent is not subject in principle to any limitations. It can, for example, be a cleansing agent, such as shampoos, care agents, such as hair treatments and hair rinses, setting agents, such as hair setting lotions, hair sprays and blow-waving lotions, permanent shaping agents, such as permanent waving agents and fixatives, coloring agents, such as bleaching agents, oxidation dyes and tinting agents based on direct dyes, hair tonics and split-end fluids. Accordingly, the preparations can be formulated as aqueous or aqueous-alcoholic (with a maximum of 15% by weight of alkanol, based on the total agent) solutions, emulsions, gels, creams, aerosols or lotions.